The cancer jargon dictionary: 25 terms you need to know

Topics: Public Health, Diseases & Conditions, Cancer, Industry, Biotech, Prescription Drugs, Care Delivery

By Jackie Kimmell, Senior Analyst  

There's a lot of jargon in health care, and are few medical fields more complex than oncology. While the field has made significant advancements in recent years, it can be hard to fully understand new advancements without understanding the basics. To help demystify the jargon, we've found and defined 25 oncology terms you should know.  

Types of cancer

There are more than 100 types of cancer, according to the National Cancer Institute. Those types are commonly named for the organs or tissues containing the cancerous cells, as well as the type of cells that created the cancer. But within that list, here are some of the most common terms everyone should know.   

  • Carcinoma: The most common type of cancer which forms in the tissues that line the internal organs, like the liver and kidneys.
  • Leukemia: A type of cancer that occurs in the blood-forming cells of the bone marrow. When one of these cells becomes cancerous, it often replicates quickly and enters the bloodstream to spread through the body.
  • Lymphoma: A type of cancer that occurs in the lymphatic system, which is the part of the body's immune system.
  • Melanoma: A type of cancer that begins in melanocytes (cells that make the pigment called melanin). It often grows in a mole on the skin.
  • Myeloma: A type of cancer that occurs in plasma cells, a type of white blood cell.
  • Sarcoma: A type of cancer which begins in the bone or soft tissues, including fat, muscle, blood vessels, cartilage or other supportive or connective tissues.

Clinical terms to know  

Now that you know the types of cancer, it's helpful to understand how to describe and discuss those cancers in clinical terms.

  • Benign: A tumor that is not cancerous and has a low risk of attacking nearby tissue or spread to other parts of the body.
  • Bone marrow: The soft tissue in the center of large bones where stem cells (the precursor to immune cells) are created. Some cancer patients may receive a bone marrow transplant to replace their stem cells which have been destroyed by cancer or cancer treatment.
  • Malignant: A tumor that is cancerous and at risk for invading nearby tissue or spreading into the body.
  • Metastasis: When cancer spreads from the place it began to another part of the body. This is different from "locally advanced" cancer which has spread to nearby tissues or the lymph nodes, but not throughout the body.
  • Oncogene: A mutated form of a gene which is involved in normal cell growth. Oncogenes may cause the growth of cancerous cells and are often either inherited or caused by environmental exposure.
  • Polyp: A growth of tissue that sticks out from the mucous membrane (a tissue that lines many body cavities). Polyps often occur in the colon, and are usually benign, although they can sometimes become malignant.
  • Recurrence: Cancer that has come back after a period of time during which it could not be detected. It can come back to the original site ("local recurrence"); near the site or nearby lymph nodes ("regional recurrence"); or to other parts of the body by travelling through the lymph nodes or bloodstream ("distant recurrence").
  • Tumor: An abnormal mass of tissue that results when normal cells divide more than they should or do not die when they should. A tumor can be benign (noncancerous) or malignant (cancerous), and can also be called nodules or neoplasms.

Treatment terms to know

Now that you understand the main types of cancer and how they can present, it's important to know the terms that describe some of the most common diagnosis and treatment methods.  

  • Ablation: The removal or destruction of a body part or tissue, often tumors in oncology. This can be performed by surgery, hormones, drugs, radiofrequency (using radio waves), heat or other approaches.
  • Biopsy: A procedure in which a small part of tissue is taken for examination under a microscope to see if cancer is present.
  • Chemotherapy: A treatment that uses drugs to stop cancer cell growth, either by killing cells or preventing them from dividing. It can be given orally, by injection, by infusion, or on the skin, depending on the type of cancer and the stage it's in.
  • Embolization: A procedure that uses small particles (like gelatin sponges or beads) to block the flow of blood to a tumor or abnormal area of tissue. It can be used to treat some types of liver cancer, kidney cancer or neuroendocrine (hormone producing cells) tumors.
  • Neoadjuvant therapy: Treatment given as a first step before the main treatment, which is often surgery. It may include chemotherapy, radiation therapy or hormone therapy aimed at shrinking the tumor.
  • Radiation therapy: Treatment which uses high-energy x-rays, gamma rays, neutrons, protons or other particles to kill cancer cells and shrink tumors. The most common type is from a machine outside of the body (known as external-beam radiation therapy), although it can also come from radioactive material placed in the body (known as internal radiation therapy or brachytherapy).

New innovation terms to know

The oncology field is always innovating and advancing care. In the past few years alone, we've seen several advances to improve diagnostics and treatments.

  • CAR T-cell therapy: A type of treatment in which a patient's T cells (a type of immune cell) are taken from their blood, modified in the laboratory to include a special receptor that binds to cancer cells, grown in large numbers, and then infused back into the patient.
  • BRCA gene: BRCA1 and BCRA2 genes help to suppress cell growth. About .2-.3% of the population (and 2.5% of the of the Ashkenazi Jewish population) has a mutation in one of these genes that puts them at higher risk of getting breast, ovarian, prostate, and other types of cancer.
  • Immune checkpoint inhibitors: A type of drug that blocks certain proteins which, in a normal immune system, act as a "break" on T cells (a type of immune cell). When these proteins are blocked, it allows T cells to more aggressively kill cancerous cells.
  • Liquid biopsies: A test to detect cancer from blood samples (or, less often, from urine or saliva) rather than from traditional tissue samples. It often allows doctors to find cancer at an earlier stage and can also be used to help plan treatment.
  • Radiosensitivity testing: A type of molecular test that identifies generic markers that show how tumors are likely to respond to radiation. This information can then help shape treatment conversations, such as if the patient would benefit from radiation therapy, and what type or dose they should receive.
  • Stereotactic radiosurgery: A type of external radiation therapy used to treat brain tumors that cannot be treated by regular surgery. It is also being studied for the treatment of other types of cancer.